Apparatus for manufacturing slide fasteners



Aug. 9, 1949. M. VOlTY 2,478,880

APPARATUS FOR MANUFACTURING SLIDE FASTENERS Filed July 29, 1943 4Sheets-Sheet 1 INVENTOR MnuR/ce' Vo/ry 5 $TORNEY Aug. 9, 1949. M. van2,478,880

APPARATUS FOR MANUFACTURING SLIDE FASTENERS Filed July 29, 1943 4Sheets-Sheet 2 fl i522.

A TORNEY 1949- M. VOlTY 2,478,880

APPARATUS FOR MANUFACTURING SLID E FASTENERS Filed July 29, 1943 4Sheets-Sheet 3 INVENTOR Mun/c6 VO/TY m BY v-d 2 ATORNEY Aug. 9, 1949. M.VOITY 2,478,880

APPARATUS FOR MANUFACTURING SLIDE FASTENERS 4 Sheets-Sheet 4 Filed July29, 1945 Patented Aug. 9, 1949 APPARATUS FOR MANUFACTURING SLIDEFASTENERS Maurice Voity,

Slide Fasteners, York Bayside, N. Y., assignor to Serval Inc., acorporation of New Application July 29, 1943, Serial No. 496,571

This invention relates to an apparatus for manufacturing slide fastenersfrom long strips.

The principal object of the invention is to provide an apparatus of thecharacter described, which can operate at speeds greatly in excess ofthose. now attained without sacrificing precision in severing andclamping the slide fastener elements. At the present time apparatuses ofsimilar character run at about 2,100 cycles of operation per minute. Inaccordance with the present invention I'attain speeds of from 3,250 to4,500 such cycles per minute.

A further object of the invention is to provide an apparatus of thecharacter described which, in spite of its remarkable speed, shall havesuch durability that it can run for months without repairing orreplacing parts other than the severing and clamping dies.

Another object of the invention is to generally improve an apparatus ofthe character described, particularly in relation to the severing andclamping apparatus shown and described in my copending application forMethod and apparatus for manufacturing slide fasteners, Serial No.436,279, filed March 26, 1942, now Patent No. 2,396,933.

Other objects of the invention will in part be obvious and in parthereinafter pointed out.

The invention accordingly consists in the features of construction,combinations of elements and arrangement of parts which will beexemplified in the construction hereinafter described and of which thescope of application will be indicated in the appended claims.

In the accompanying drawings in which is shown one of the variouspossible embodiments of this invention,

Fig. 1 is a top plan view of an apparatus embodying the presentinvention;

Fig. 2 is an enlarged sectional. view therethrough taken substantiallyalong the line 2--2 of Fig. 1, and is illustrative of the improvedmechanism employed to actuate the tape feeding means from the driveshaft;

Fig. 3 is an enlarged sectional view taken substantially along the line3-3 of Fig. 1, and is illustrative of the improved mechanism employed tointermittently stop the strip feeding means in order to provide spacesbetween groups of slider elements clamped on a tape;

Figs. 4 and 5 are enlarged sectional views taken substantially along thelines 4-4 and 55 respectively of Fig. 1, and are illustrative of theimproved mechanism employed to actuate the clamping means from the driveshaft;

4 Claims. (01. 153-1) Fig. 6 is an enlarged sectional view takensubstantially along the line 6--6 of Fig. l, and is illustrative of theimproved mechanism employed to actuate the severing means from the driveshaft;

Fig. '7 is an enlarged sectional view taken along the line 1-1 of Fig.1, and is illustrative of the improved mechanism employed to actuate thestrip feeding. means from the drive shaft; and

Fig. 8 is an enlarged sectional view taken along the line B'-8 of Fig.'7, and is illustrative of the construction of .a self-aligninganti-friction bearing.

In general how I attain the objects of this invention will be understoodfrom the following considerations:

For a long time in the design of machines of the character described ithas been customary to employ cams and followers for actuating thevarious operative means (strip feed, etc., hereinafter referred to) fromthe drive shaft, heavy back springs having been used to hold thefollowers against the cams. By embodying various refinements, such aslightening and balancing of parts and using a single drive shaft, thesemachines were brought up to speeds of about 2,100 cycles per minute. Butwhen attempts were made to further substantially increase their speedthe machines ran asynchronously, severed and clamped elementsinaccurately, wore rapidly, and overheated, quickly despite the use ofelaborate oiling systems and excellent anti-friction bearings.

In accordance with my invention, I provide actuating mechanisms for thevarious operative means whereby unusually high speeds of operation areobtained, considerably in excess of the highest speed obtainableheretofore, without entailing the difficulties and disadvantages abovementioned. In this aspect of the invention I have departed from theattempts others have heretofore made to obtain speed increases bychanges in the operative means themselves, but have directed myimprovements rather to the actuating mechanisms which hitherto by theirvery nature have prevented attaining such higher speeds.

In general I provide positive actuation of the operative means byeccentric sheaves and rods. Certain of the operative means, for examplethe means for feeding the strip and the means for clamping elements onthe tape, oscillate about axes not parallel to the axis of the driveshaft and shift transversely of the eccentrics. I over-. come the effectof such shifting by swiveling the eccentric rods at both ends, as onself-aligning anti-friction bearings. The term "anti-friction bearing,as employed herein, denotes a bearing having a plurality of rollingcontact elements, such as a roller bearing or ball bearing. I have foundthat this generates but little heat, is very durable and does notnoticeably increase the stress on any of the rapidly moving parts,

Heretofore the mechanism for providing gaps between groups of elementshad taken advantage of the impositive connection between the cam andfollower and held the follower at its point of maximum departure fromthe drive shaft so that continned movement of the cam would not affectany feed of the strip. I have retained this simple interrupting means byproviding an impositively driven member in the strip feeding meansitself.

General description of machine Referring now in detail to the drawings,to denotes a stringer fabricating machine embodying the invention andadapted to operate upon a preformed strip S such as shown and describedin detail in my said copending application. This strip, as is wellknown, may comprise a series of closely spaced projections andassociated'underlying depressions arranged longitudinally of the stripand provided with lateral flats. The longitudinal edges of the strip aretoothed to facilitate the formation of square corners on the jaws of theslide fastener elements. It should be understood, however. that theformation of the strip has no bearing on the improvements in theamachine forming the subject matter of the present invention.

The machine It essentially comprises four operative means which areintermittently actuated in properly timed relationship once everyrevolution of the drive shaft l2. These are a means H for feeding thestrip S, a means It for feeding the tape T, a means 18 for severing theforemost slide fastener element from the strip '8, and a means 20 forclamping said element on the tape T. These four means are the essentialactive operating parts of the machine and are those which in accordancewiththe present invention are actuated by eccentric sheaves and rodsfrom the drive shaft I2.

Said drive shaft is mounted for horizontal rotation in two main bearings22, 24 bolted to the bed 26 of the machine and a side bearing 28attached to an edge of said bed. The drive shaft may be actuated in anysuitable fashion as through a pulley 30 which is connected by a belt 32to the drive pulley of an electric motor M (schematically indicated). Ahand wheel 34 may also be provided to turn the drive shaft l2 over byhand when the machine is set up.

The four operative means will now be briefly outlined and the mechanismsfor actuating each described in detail.

The strip feeding means and associated structure The prefabricated strip8 which is supplied from a reel (not shown) slides over the oiling padof a strip lubricating box 86 (Fig. 1) and is advanced during aninterval preceding the cutting and clamping of a. slide fastener elementby the strip feeding means 14. Said means comprises a feed dog fitting38 pivoted on a post 40 pro- :Iecting upwardly from the bed 28. Thefitting- 38 includes a barrel 42 lined with a sleeve 44 (Fig. 3) inwhich the plunger 46 of a shaft 48 is slidably received. A heavy backspring 50 encircling the shaft 48 urges the plunger 48 in the directionof travel of the strip 8 (indicated by the arrow ,A)

' cap 54 serves to and tapped to threadedly retain a flanged bushing 58through which the shaft 48 freely extends, The portion of said shaftprojecting beyond the bushing is threaded to accommodate nuts 60 whichare of such external dimensions as to abut against the rear of thebushing 58 under pressure of the back spring. A. set screw 62 threadedinto a tapped aperture in a ridge 64 (Fig. 1) on the lock the bushing 58in any adjusted position.

Manipulation of the bushing regulates the extended position 46'withaccuracy and case.

To prevent rotation of said plunger, the forward end thereof isvertically elongated to provide a head 66 which is horizontally slidablein a slot 68 running down the front of the barrel 42. The front face ofthe head 66 is likewise slotted to accommodate a feed element or dog 69.this latter slot being bridged near the bed 26 by a horizontal shaft 10extending normal to the direction A of strip feed and carrying theradially secured feed dog. One end of the shaft 10 which projects beyonda side of the'head 66 has an arm 12 affixed thereto which is encircledby a torsion spring 14. Said spring is anchored at one end to a screw 76secured in the plunger head 66 and at the other end has a bent legpassing through a hole in the arm 12 so that it biases theshaft 12 in acounterclockwise direction as viewed from Fig. 3. This permits the feeddog 69 when operatively moved in the direction A of strip feed to engagea projection on the strip s and push said strip toward the severingmeans l8. It also permits the feed dog to rotate clockwise against thetorsional pressure of the spring 14 when pulled back over the nextsucceeding projection during its retrograde stroke.

Pursuant to the principal object of my invention, I operate the stripfeeding means M from the driveshaft I 2 with a positive actuatingmechanism such as an eccentric sheave 18 (Fig. 7) and eccentric rod 80.The eccentric sheave 78 is fixed to the driveshaft with a key 82 and isforce-fitted in the inner race 84 of a. sel -aligning anti-frictionbearing 86, the outer race 88 of said bearing being secured in the strapend 98 of the eccentric rod 80.

The term self-aligning hearing" as employed herein denotes a bearingwhose outer race can oscillate about an axis perpendicular to the axisof rotation of the inner race and vice versa. A section through such abearing is shown in Fig. 8.

58 and nuts 60 of the plunger As is apparent from this figure, thebearing 86 may include an inner race 84 having two confining grooves 92in which two rows of balls 94 are'held. The balls are kept in rows by acage 96 which also spaces them in staggered relationship, 1. e., with aball in one row between two spaced balls in the other row. The outerrace 88 has on inner spherical surface 98' which rides on the 80 islikewise provided with a split collar I02 and clamping screw I04. Saidcollar carries a small self-aligning anti-friction bearing I08 securedto a stud I08 on the feed dog fitting 38 extending at an angle to theplane in which the eccentric sheave 18 rotates.

By employing the self-aligning bearings 86 and I06 in the actuatingmechanism for the strip feeding means the eccentric rod 80 is permittedto swivel at two points, to wit, (1) where it is connected to theeccentric sheave 18. and (2) where it is connected to the stud I08. Inthis manner I avoid providing lost motion between the eccentric sheaveand feed dog fitting to compensate for oscillation of said fitting aboutan axis aparallel to the driveshaft.

Although the connection between the drive shaft I2 and fitting 38 ispositive, the strip feed means is so constructed, as described above,that lost motion is present between said fitting and the feed dog 69.This construction is utilized to stop feed of the strip when gaps are tobe formed between groups of slide fastener elements on the tape T. Torender the strip feeding means ineffective, even though positivelyactuated, I provide an element which is projectible into the path of theplunger 46 near the end of its retrograde or non-feeding stroke. Such anelement may consist of a hardened steel pin I I0 which is operated by asolenoid III and travels along a line transecting the 'path of travel ofthe plunger head 66. The pin is normally maintained in retractedposition by a spring H2 in the solenoid housing II3. However, when theelectric circuit from the source of power P for energizing the'solenoidis closed by a micro-switch 4 which is actuated by a counter II6, thesolenoid overcomes said spring H2 and thrusts the pin II 0 into the pathof travel of the plunger head 66 to block the same.

If at the instant the pin is urged into blockin position the head is notnear the end of its retrograde stroke, the pin will merely ride on theside of the head, but shortly thereafter, when the pin clears the frontface of the head, it will quickly spring into blocking position. Aslight clearance is provided between the pin and front face of the headin extreme retrograde position so that the pin can be retracted easilywhen the fitting 38 is at the end of its retrograde stroke.

I have found that even at the extreme speed of 4,250 cycles per minute,of which the apparatus I0 is capable, the foregoing constructionoperates efliciently to space groups of elements and control the numberof elements in each group with absolute accuracy.

A check dog I20 is employed to prevent the strip S from being pulledback during retrograde movement of the feed dog 69. Said check dog isradially fixed in a shaft I22 journalled in a block I24, and operates ina slot I26 running down the front face of said block. The undersurfaceof the block is grooved to permit passage of the strip. To facilitateadjustment of the check dog, the block I24 is slidably received in acasing I28 set on the bed 26. The block is biased rearwardly by a springI30 against the tip of a bolt I32 which can be adjusted by manipulationof its knurled head I34. The bolt is fixed in adjusted position by a setscrew I36.

It will be perceived that by employing screw adjustments, I am able toprecisely locate the feed and check d-ogs-a matter of importance in ama-. chine running at the high speed attained by my apparatus. In suchan apparatus it is imperative to have the foremost slide fastenerelement 10- cated exactly relative to the severing means I8 prior tosevering and clamping said element. A

piloting mechanism, as for example that shown in Tape feeding means andassociated structure The means I6 for feeding the tape is conventionaland may be the same as that shown and described in my said copendingapplication. This means includes a knurled drum I38 rotated by a shaftI40 which is journalled in a bearing I42. To expedite the clampingaction, later described, the bearing is canted to dispose the shaft I40at an angle'to the drive shaft I2 in both plan and elevation.

The drum shaft I40 carries a ratchet wheel I44 which is turned by a pawlI46 (Fig.2) pivotally mounted on one arm of a bell crank lever I48, andpressed against said wheel by a spring I41. The bell crank lever isrotatably mounted on the shaft I40 and has fixed to its other arm a studI48 which is secured to the inner race of a selfaligning anti-frictionbearing I50. The outer race of said bearing is clamped in the splitgudgeon end I52 of an eccentric rod I54 which actuates the tape feedingmeans. The split strap end of this rod is clamped about the outer raceI56 of another self-aligning anti-friction bearing I56 whose inner raceI60 is force-fitted on an eccentric sheave I62 keyed to drive shaft I2.

Although the aparallelism of the drum shaft I40 and driveshaft I2 isslight and an ordinary bearing might function satisfactorily at arelatively low speed of 2,000 cycles per minute, I have found that wherethe speed is increased to over 3,000 revolutions per minute, vibration,stress and wear are materially lessened by the use of selfaligninganti-friction bearings. In addition, these bearings permit wideadjustment of the plan and elevation angles of the drum shaft I40 tofacilitate operation of the clamping means.

A check pawl I64 is pivotally mounted on a post I66 secured to thepedestal I68 which supports the drum bearing I42. Said pawl is urged bya spring I10 against the ratchet wheel I44 to aid in preventingretrograde movement or chattering of said wheel during the non-operativestroke of the feed pawl I46.

A smooth-faced shoe I12 pivotally mounted on the lower end of a rod I14is resiliently pressed against the tape T by a compression spring I16 toinsure good frictional contact between the tape and drum I38. Said rodI14 is slidably supported by a bracket I18 extending from the drumbearing I42. This bracket also serves to provide a thrust surface forthe upper end of the compression spring I16. The usual nuts I arescrewed on the top of the shaft I14 to provide for adiustlng thepressure of the shoe I12 on the tape T and a conventional cam I82 andfollower ring I84 allow shoe pressure to be wholly released when thetape is being threaded through the machine. A pin I86 facilitatesturning of said follower ring.

The tape is fed from a spool (not shown) to the machine I0 throughformed tensioning shoes I86,

I 30 beneath the bed 26 (Fig. 3), one of said shoes I63 being stationaryand the other I90, which is supported on a pivoted lever I32, beingurged against the stationary shoe I66 by a spring I94. A knurled handleI96 (Fig. 1) may be employed to vary the tension.

The tension imposed on the tape is appreciable and sometimes causes thetape to break at a point where the ends of two pieces are attached.Since machines of the character described run automatically and are not.under close surveillance, when a break does occur the machine continuesto go through its regular cycle of operations, cutting oil? elements andattempting to bend the jaws thereof about the bead of the missing tape.Such continued operation causes the machine to become littered with amass of severed and partially mutilated slide fastener elements whichaccumulate very rapidly at or above 3,250 cycles per minute. With aboutten per cent allowed for the periods when the strip is not fed, close to3,000 elements a minute are discharged into the small space around thesevering and clamping dies. These elements not only clutter up themachine, but in short order jam between stationary and moving parts ofthe various operative means and often lead to deformation and breakageof parts. To overcome this diiliculty, which is particularly troublesomein ultra high speed machines such as herein disclosed, I have, inaccordance with a subsidiary feature of my invention, provided animproved mean for stopping the machine I in the event that the tapebreaks. This means for stopping the machine is controlled by the tapeand in general comprises a tape break detector, that is, a means whichis sensitive to the continued presence of the tape in the region nearWhere severing and clamping occur and means. governed by the detector,for opening the circuit which supplies electric power to the motor M.The tape break detector consists of a micro-switch I91 (an extremelysensitive electric switch) which is housed in an elongated pencil-likecasing I98 from whose forward tapered end a finger 200 protrudes. Thecasing is so supported on the machine by a flexible mounting 202 thatthe finger 200 rides on the taut moving tape T and is pressed therebyinto the housing I98 against the action of a spring 204 within saidhousing. Said finger when urged into the casing I 98 closes themicro-switch and completes the circuit energizing the motor M. When thetape breaks, the spring 204 will thrust the finger out, opening themotor circuit at the micro-switch I91 and thus stopping operation of themachine Ill.

The severing means and associated structure The severing means I80, inits general aspects, is largely conventional. It comprises a head 206bolted to the bed 26 and having ways 208 in which a ram 2! ismounted forvertical reciprocation. The ram carries a shearing die 2I2 whichcooperates with an anvil 2 I4 to sever the foremost slide fastenerelement from the strip S. The ram is urged to its extreme upper positionby a compression spring (not shown) which presses against a top plate 2I 6 on the ram and is bottomed against the base of a well (not shown) inthe head. Said ram is intermittently forced down against the action ofthe compression spring by a screw 2! adjustably carried on the drivingend 220 of a ram lever 222 (Fig. 6). The lever is journalled on acountershaft 234 spanning the main bearings 22, 24 above the drive shaftI2. To reduce fric- 8 tion at this point an anti-friction bearingrotatably connects the lever 222 and its shaft 224. Such anti-frictionbearing, in the illustrated embodiment of my invention, comprises aneedle or roller bearing 226 entirely housed within a heavy hub 228forming an integral part of the ram lever 222. The driven end of saidlever consists of a pair of parallel arms 230 having aligned terminalcollars 232 in which is force-fitted a shaft 234 whose central portionis pressed into the inner race of an anti-friction bearing 236, such asa double row ball bearing. The outer race of this bearing is pressedinto the gudgeon end 238 of an eccentric rod 240 whose strap end 242 hasthe outer race of another anti-friction bearing 244 tightly securedtherein. The inner race of this latter bearing is pressed-fitted in aneccentric sheave 246 keyed to the drive shaft I2. The last mentionedbearing 244 may, like the anti-friction bearing 236, be of the doublerow ball bearing type. It will be noted that the three anti-frictionbearings 226, 236 and 244 employed in the actuating mechanism for thesevering means are not of the self-aligning type since the shafts 234and 224 are parallel to the drive shaft. I2. However, it will beunderstood that if the machine is so constructed that the severing meansincludes an element actuated from the drive shaft and oscillatable abouta counter-shaft aparallel to the drive shaft I2 that self-aligninganti-friction hearings will be employed at the two ends of the eccentricrod interconnecting this element and the eccentric sheave for actuatingthe same.

The clamping means and associated structure During the time that theforemost slide fastener element is severed from the strip S, its jawsare clamped about the head of the tape T. The clamping means 20, whichperforms this operation, comprises a pair of levers 250, 252, each ofwhich is independently fulcrumed on a separate pivot pin 254, 256. Thesepins are supported on the bed 26 and have a bridging plate 258connecting their tops to reinforce the same. The ends of the leversextending towards the ram 2 I0 carry clamping blades 260 of conventionalconstruction, the same being shown and described in my said copendingapplication.

Each of the levers has at its opposite end a stud 262, 264 which extendstherefrom and is force-fitted in the inner race of one of a pair ofself-aligning anti-friction bearings 266, 266. The firstof thesehearings 266 is a ball bearing whose outer race is clamped in a splitcollar 210 on the gudgeon end of an eccentric rod 212 whose split strapend 214 is clamped about the outer race of another self -aligning ballbearing 216. The inner race of this latter ball bearing 216 is pressedon an eccentric sheave 216 keyed to the drive shaft I2. The secondself-aligning bearing 268, also a ball bearing, is secured to the smallend of an eccentric rod 280 whose large end is attached through themedium of a self-aligning ball bearing 282 to an eccentric sheave 284keyed to the drive shaft l2.

As is apparent from inspection of the eccentric sheaves 218, 284 theclamping jaws on the levers 250, 252 will reciprocate oppositely andpress together the spread legs of a slide fastener element severed fromthe strip whereby to clamp the same about the head of the tape.

The bed 26 has arcuate recesses 286, 286 beneath the strap ends of thetwo eccentric rods 280, 212 to provide clearance therefor. Similarrecesses are formed beneath the strap ends of the 9 previously describedeccentric rods 90, I54 and 240.

The operation of the machine The timing of the various Operative meansis such that first the tape is advanced the distance ment on said stripastride the tape bead, the head of this element resting upon the anvil2|. The

strip feeding means does not operate again in the same cycle.

As soon as the strip has come to rest the ram 0, which may have begun tomove during the strip feed, comes into play. Said ram may firstaccurately position the strip with its piloting teeth 290 and thensever'the foremost slide fastener element. This element may remainstationary while it is cut from the rest of the strip and the portion ofthe strip immediately behind the sameallowed to depress on a floatingpad 292. While the severing operation is taking place, and preferablybefore the same has been completed so that control over theelement-being attached is maintained, the clamping means begins tofunction to press the spread jaws of the element being severed aroundthe bead of the tape. The ram can now be withdrawn and opened to freethe attached element.

This completes the cycle and advance of the tape andstrip commences anew cycle of operations. v

The advantages of the machine As indicated, the main novel effectsecured by my improved construction is the truly remarkable speed whichthe machine can attain. An attaching apparatus constructed in accordancewith my copending application has an optimum speed of 2,100 cycles perminute, the term "optimum" indicating a speed at which wear and breakageof moving parts other than the dies are not appreciable. When thismachine is, run at a much higher speed,for example, 3,000 cycles perminute, the moving parts break in short order, excessive vibration isdeveloped, parts which do not break are found to have worn greatlyduring the few minutes which they ran at excessive speed, and the slidefastener elements which have been attached are not properly positioneddue to asynchronous operation of the operative means.

With my improved apparatus, however, at a speed of 3,250 cycles perminute, perfect timing is maintained, no noticeable vibration ispresent,

the apparatus functions very quietly compared to the clatteringoperation chines at lower speeds, and the apparatus, will run for alongtime without requiring any replacement for wear or breakage other thandies;

is a marked improvement over present-day attaching machines in which thecams and followers must frequently be replaced or repaired.

This improvement is due wholly to the use of eccentric sheaves andeccentric rods, as I have found that, if any one or more of theseimproved actuating mechanisms is replaced by a conventional cam andfollower, the machine will nolonger operate efficiently at greater than3,000 cycles per minute.

It will thus be seen that I have provided an apparatus for making slidefasteners which achieves the several obiects of this invention and theclamping jaws of the present-day ma necting each 1 0 which is welladapted to meet practical me.

As various possible embodiments might be made of the above invention andas various changes might be made in the embodiment above set forth,

it is to be understood that all matter herein-set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense, the invention being defined in the following claims.

Having thus described my invention, I claim as new and desire to secureby LettersPatent:

1. A high speed apparatus for severing slide fastener elements from along strip and clamping the same on a tape, said apparatus comprising asingle drive shaft,-a plurality of operative meansfor severing elementsfrom the strip, for clamping elements on the tape, for advancing thestrip and for advancing the tape, and separate actuating mechanisms forpositively actuating each of said operative means from said drive shaft,each of said actuating mechanisms including an eccentric sheave on saiddrive shaft, an eccentric rod consheave to its associated operativemeans, and an anti-friction bearing intermediate each sheave andeccentric rod.

,2. A high speed apparatus for severing slide fastener elements from along strip and clamping the same on a tape, said apparatus comprising asingle drive shaft, a plurality of operative means for severing elementsfrom the strip, for clamping elements .on the tape, for advancing thestrip and for advancing the tape, and separate actuating mechanisms forpositively actuating each of said operative means from said drive shaft,each of said actuating mechanisms including an eccentric sheave on saiddrive shaft, an eccentric rod connecting each sheave to its associatedoperative means, and an anti-friction bearing intermediate each sheaveand eccentric rod and intermediate each eccentric rod and its associatedoperative means.

3. An apparatus, as set forth in claim 2, wherein the anti-frictionbearings associated with at least REFERENCES CITED The followingreferences are of record in the file of this patent:

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